Method for protecting plants against oxidant injury

ABSTRACT

A method for protecting plants against oxidant injury comprising topically applying one or more compounds containing a methylenedioxyphenyl radical.

United States Patent Takaoka et al.

Assignees: Takasago Perfumery Co., Ltd.; The

Japan Tabacco & Salt Public Corporation, both of Tokyo, Japan Filed: Aug. 9, 1973 Appl. No; 386,892

Foreign Application Priority Data Aug. 15, 1972 Japan 47-8ll62 NOV. 18, 1975 [52] U.S. Cl 71/88; 7l/94 [5l] lnt. Cl. AOIN 9/24 [58] Field of Search 71/88, 78

Primary E.wminer-Lewis Gotts Assistant Examiner-Catherine Lv Mills Attorney, Agent, or Fz'rmSughrue, Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT A method for protecting plants against oxidant injury comprising topically applying one or more compounds containing a methylenedioxyphenyl radical 3 Claims, N0 Drawings METHOD FOR PROTECTING PLANTS AGAINST OXIDANT INJURY BACKGROUND OF THE INVENTION l. Field of the Invention The present invention relates to a method for protecting plants against oxidant injury.

2. Description ofthe Prior Art With the development of industry and due to increasing exhaust gases as a result of an expanding number of automobiles. air pollution recently has prevailed over the world. Air pollution causes injury to cultivated plants which becomes more severe year by year. It is particularly remarkable that agricultural and horticultural cultivated plants. trees. etc. are injured by oxidants which are a portion of air pollutants. As protecting agents against oxidant injury in plants, antioxidants; bcnomyl agents (M. Pcllissier, N. L. Lacassee, et al.: Journal of the Air Polution Control Association. 22. No. 9, 722 725 (1972)); diphenylamines, quinones, thiocarbamates (S. Rich and G. S. Tayler: Science 132, I50 l5l (l960)); plant hormones such as kinetin and benzyladenine are known. However, they have various practical disadvantages in that they show low protecting effects, result in colored deposits. give rise to toxic effects to man and animals. adversely affect the physiological functions of plants. etc.

SUMMARY OF THE INVENTION An object of this invention is to protect plants from injury by oxidants.

Another object of this invention is to provide a protective agent against oxidant injury in plants which can be produced from easily available industrial chemicals.

A further object of this invention is to provide a safe protective agent against oxidant injury in plants which is not toxic to man and animals and does not cause damage to plants.

These and other objects ofthis invention will be more clearly understood referring to the following detailed description and examples.

The inventors have studied many compounds for protecting plants from injury by oxidants. as a result. have found that agents containing as an active ingredient compounds having a methylcnedioxyphenyl radical are effective for protecting plants from injury by oxidants.

The compounds having a methylenedioxyphenyl group according to this invention exhibit potent protecting effects against oxidant injury in plant when pre viously sprayed on the plants in the form of an emulsion or a suspension of a wettable powder. Moreover. these compounds have no acute toxicity and neither give rise to toxic effects to man and animals nor injury to plants.

DETAILED DESCRIPTION OF THE INVENTION Compounds having methylenedioxyphenyl radical are those having the radical in their structural formula and include, for example, sesamin. sesamolin. piperine. piperonyl butoxide. sesamex, sulfoxide, propyl isome, safroxan, piperonyl cyclonene, methylenedioxycinnamic acid. halfsesamin, piperonal and methylenedioxy phthalaldehyde. These compounds are those which are found in natural products or produced as a synergist for insecticides. perfumes and industrial chemicals, which can be used for the purposes of this invention without adversely affecting man and animals as well as plants. That is, sesamin (p. 943) (The numerals in parenthese indicate pages of The Merck Index 8th Edition in which the compounds are described.) and sesamolin (p. 944) are found in a sesame oil, piperine (p. 838) is found in black pepper and piperonyl butoxide (p. 839), sesamex (p. 943), sulfoxide (p. 1004), propyl isome, safroxan. piperonyl cyclonene, etc. are known as synergists for insecticides. In the following Table 1, compounds containing a methylenedioxyphenyl radical are tabulated along with their chemical structural formulas and properties.

Table 1 Compound Structural Formula Property CH CH CH 1 Piperonyl H 2 2 5 Light:

butoxide 2 brown oil C11 (OCH CH O(J H O 2 Safroxan H C D@ White solid a j I eH e ea sesamolin l-i C O CH C}liih1te solid COLLL H5 40 A Piperonyl H C Red oily Cyclonene 0" liquid 4 Table lContinued Compound stiructurgl Fgrmulg, Ptofitx 5 Sesamex H T Yellow 2 \O O-Ch(OL1I C1i u,H CH o l llquld 6 Sesamin H C b 9 I 2 White solid 0 i i @:Z CH

CH /CH 2 CH White oily '7 Sulfoxide H C 2 a -cu- (cii cii llquld 0 (3000 11 0 3 7 White 8 Propyl Isome H C Orange 0 on oily liquid /0 l l? D wh" 1" 9 Plperlne H C 0/ CH:CHCH=CH C N me so in fiizg 0 CH -CH=CH-COOH mm lid 10 Cinnamic Acid r2 1 e Y 11 e ow ll Halfseuamln H C 0:@) oily liquid 0 12 Piperonal H C CH0 White solid 13 l iethylene- H I CH0 Light dioay Phtha- 2 CH0 yellow solid laldehyde These compounds show an potent protecting effect on plants from injury caused by oxidants. when previously sprayed in the form of an emulsion or a suspension containing about 0.01 to 1.071 preferably about 0.05 to 0.2% by weight of one or more of these compounds.

In the preparation ofthc protective agent against oxidant injury according to this invention, the compounds shown in Table I may previously be in the form of an emulsifiablc concentrate prepared in an appropriate solvent containing adequate surface-active agent (0.5 to 5% and dispersing agent (0 to 5% and then used by diluting. while stirring. with water. In the case of compounds which are solid at normal temperatures, they are advantageously in the form of a wettable powder prepared by powdering with a carrier (30 to and an dispersing agent (0 to 10%) and then used by diluting with water.

As solvents. surface-active agents and Spreaders, the following compounds are suitable.

Solvents: mixtures of aliphatic or alicyclic hydrocarbons and alcohols; aromatic hydrocarbons such as benzene. toluene and xylene; ethcrs such as propyl ether and dioxane; ketones such as acetone. methyl ethyl ketone and acctophenone; esters such as tributyl phosphate. triethyl phosphate. ethyl acetate. amyl acetate.

benzyl acetate and methyl phthalate; alcohols and glycols such as ethyl alcohol, isopropyl alcohol, n-butyl alcohol, n-hexanol, ethylene glycol, 2-ethyl-l,8-hcxanediol, cyclohexanol, benzyl alcohol and propylene glycol; ether alcohols such as methyl cellosolve, butyl cellosolve, diethyleneglycol monoethylether and diethyleneglycol monobutylether; dimethylformamide, dimethylacetamide, etc.

Surface-active agents: polyoxyethylene higher alcohol ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene fatty acid esters, fatty acid monoglycerides, fatty acid glycol esters, polyoxyethylene sorbitol fatty acid esters, polyoxyethylene fatty acid amides and amines, polyoxyethylene phosphoric acid alkyl ethers, polyoxyethylene phosphoric acid alkyl esters, polyoxyethylene phosphoric acid alkyl aryl ethers, polyoxyethylene phosphoric acid alkyl aryl esters, sulfonated oils, sulfone compounds and their esters, invert soaps, etc.

In the above described surface-active agents, the degree of polymerization of the polyoxyethylene group generally used is about 10. Suitable alkyl aryl groups are generally nonyl phenyl or octyl phenyl. Higher alcohols generally employed are the C and C alcohols and the fatty acids generally are the C to C fatty acids, the number of carbon atoms in the alkylphosphoric acid esters is generally 8 to 9.

Dispersing agentszligninsulfonates, fatty acid ethyl esters, abietic ester, alkylnaphthalenesulfonates, alkylbenzensulfonates etc.

The following specific examples of the preparation of this protective agent against oxidant injury in plants will be illustrated using the compounds described above. Unless otherwise indicated all parts and percents are by weight.

A. Preparation examples of compounds which are liquid at normal temperature Preparation Example I Sesamex is diluted while stirring with water containing 0.I% of Tween 20 (a polyoxyethylenesorbitanemonolaurate produced by Atlas Co., Ltd.) to produce an emulsion containing 0.2% of sesamex.

Preparation Example 2 Piperonyl Butoxide 30% Ethyl Alcohol 60% Polyoxycthylene Nonyl Phenyl I% Ether These are diluted with water while stirring to produce an emulsion containing 0.05 to I.0% of piperonyl butoxide.

Preparation Example 3 Piperonyl Butoxide 20% Diacetone Alcohol 30% Sorpol (Toho Chemical Ind. 1.0% Co. Ltd. Japan) Xylol IS% Ethanol 29% Water 5% In applying, these are diluted with water to a N50 to H500 concentration while stirring to produce an emulsifiable concentrate. It is quite rapidly dispersed uniformly in water and shows a uniform effect.

B. Preparation examples of compounds which are solid at normal temperature Preparation Example 4 Safroxan 50% Dibutylnaphthalene It)% sulfonic acid-Na Bentonite 40 7,

The wettablc powder is diluted to a l/IO0 to [/1000 concentration with water while stirring to produce a suspension.

Preparation Example 5 30 parts of piperine is dissolved in 60 parts of benzene, added with 10 parts of Tween 20 and diluted with water to the concentration of 0.05 to I% while stirring to produce an emulsion.

The following application examples will be given for demonstrating the effect of the protective agents according to this invention.

Application Example l Tobacco plants (Nicotiana tabacum L. Var. Hicks-2) were cultivated in clay pots, l2 cm in diameter, and treated with the protective agents of this invention at the time when the plants with about 23 leaves were at the onset of flowering.

10 ml of piperonyl butoxide was first dissolved into 20 m1 of ethyl alcohol and then diluted while stirring with water containing 0.1% Tween 20 to the designated concentration of piperonyl butoxide.

The above emulsion was sprayed on plants in such an amount that both surfaces of the leaves were sufficiently wetted.

5 days after treating, the plants were placed in a plant fumigation chamber X X I00 cm) available from Toyo Rika Instrument Inc. which can automatically control the temperature, humidity, illumination and amount of oxidant generated. Thus, they were exposed to air containing 30 pphm (parts per hundred million) oxidant under the conditions of an illumination of 20,000 lux and a temperature of 20C for 2 hours and then placed into a greenhouse at l5C. After 48 hours, the degree of damage was evaluated for 5 individual leaves I 5th to [9th leaf from the cotyledons). The results obtained are shown in the following Table 2. Under natural conditions, the oxidant injury in cultivated plants in the field occurs at about l0 pphm ofoxidant concentration. In this test, more severe conditions (higher concentration of oxidant) were applied in comparison with naturally occurring conditions.

Each of items shown in Table 2 were evaluated in accordance with the following: (The following system is also applicable to Tables 3 and 4.)

Degree of Injury 0: No damage at all Damage to less than 20% of the leaf surface area Damage of 20 to 40% of the leaf surface area Damage of 40 to 60% in leaf surface area Damage of 60 to 80% in leaf surface area Damage of 80 to in leaf surface area a Degree of Injury Injury Index for Injury Index for Untreated Plants Treated Plants Injury Index for Untreated Plants Protection rate I00) Table 2 Application Example 3 C of Degree iury (H The preparation prepared according to the above p qgy l 16 17 1B lreal th lg t :F preparation Example 3 was diluted to a piperonyl g gz' e 23 ex 'g 'l 5 butoxide concentration of 0.2%. The following Table 4 Emulsion dons (7H shows the results of the protective effect against Spraying weather fleck which is an oxidant injury in tobacco 01,, plants in the field under natural conditions n a tobac- Emulsion: co-producing district of Okayama Prefecture in Japan.

untreated l l 3 4 4 2.6

treated 0 0 U 0 l 0.2 92 0 Table 4 Spraying 0.2% Test- Treatment Time of Time of Injury Protec- Emulsion: ing Testing Observation Index tion untreated l 2 3 4 4 2.8 N0. (days (days after Rate treated 0 0 0 l 0 O. 93 after treatment) (7U blooming) g untreated 5 5 5.2

. l Emulsion: H H

untreated l 2 4 4 3 2.3 "flied 7 treated 0 0 0 0 l 0... 93 unnamed I 2 65 l l These leaves were the most susceptible to injury h) oxidant and were the most 2 t d H I, O 7 89 suitable to evaluate the protecting activity of the agent due to their appropriate size tea e and physiological condition. umreated 2 3 I I9 treated 2.8 76 From the results shown in Table 2. the protective efi Note I: Tohacco plant used N. Tahaeum L. Var. Hicks-2. feet of plperonyl butoxlde against Oxldant lnrlury can be Note 2: Ohservalion is made for 5 leaves of lSth 19th leaf from the cotyledon. 5881'] Very significantly In Spraying the emulslfiable COn- Therefore. the expression of Injury Index is the same as in Application Test I. centrate thereof diluted to the lowest concentration (0 IeSIBd- From the results shown in Table 4, it is noted that the r 'v Application Example 2 p otecti e agent of this invention shows a protective effect against weather flecks in tobacco plants. Tobacco plants (variety: Bel w-3) which have an extremely low tolerance for oxidant injury were treated Apphcat'on Test 4 with an emulsion containing 0.2% of piperonyl butox- Tobacco plants were cultivated in the same manner idc diluted to H500 concentration in about the same as in the above Application Example I and then manner as in the application test L0. 1, 3. 7. l4 and 2l sprayed with 0.2% solutions of compounds 2- 8 shown days after the spraying, the plants were exposed to air in the Table 1 prepared in the same way as in the above containing 30 pphm oxidant concentration under the Application Example 3 y tfi the treatment. t condition of an illumination of 20.000 lux illumination Plants were exposed to Containing 20 PP madam and a temperature of forz hours and then placed 40 under the condition of an illumination of 20.000 lux in a greenhouse at l5C. After 48 hours, the degree of f a temperature of f0? 2 hours and P Injury was evaluated. The results obtained are shown in m a greenhouse at After 48 the degree of the following Table damage was observed. The results obtained are shown in the following Table 5. Table 3 Table 5 Days after Degree of Injury Pro- Treatment l5 l6 I? I8 I9" leaf Injury tec- Compound Degree of Injury Injury from the Index tion l5 l6 17 I8 I9 leaf Index Cotyle- Rate do :1 Sat'roxan (2) 0 0 l 0 0 0.2 Sesamolin (3) 0 l l 0 0 0.4 untreated 3 3 4 4 2 3.3 50 Piperonyl 0 l 0 0 0 0.2 0 Cyclonene (4) treated 2 3 4 3 3 3.0 0.1 Sesame-X (5) 0 0 0 l M Sesamin (6) 0 0 0 l 0 0.2 umreaed 2 3 4 3 3 3 0 Sulfoxide (7) O l I 0 0 0.4 3 n-Propyl 0 l O 0 0 02 [some (8) treated 0 0 0 l l 0.4 86.7 pipcrine (9) 0 I 0 O 0 0.2 Methylenedioxy 0 l 0 0 I 0.4 untreated 2 3 3 4 2 2.8 Cinnamic acid ('0) 7 Halfsesamin (ll) 0 1 l 1 0 0.6 0 l l 2 Piperonal l2) 0 l l o o 0.4 Methylenedioxy 0 l l 0 0 0.4 untreated 2 2 4 3 3 2.8 Phthaladehyde 4 (l3) treated 0 2 3 2 2 1.8 35.7 unimied 1 1 3 4 4 2.6

From the results shown in the Table 3, it is noted that the protective effect against oxidant injury of the protective agent according to this invention continues for a considerable period of time of more than about l4 days after spraying.

Application Example 5 Tobacco (Nicoliana tabacum L.), tomato (Lycopersicum esculenlum MILL). egg-plant (Solarium mologena L.), Kidney bean (Phaseolus vulgaris L.), al-

the branch tested. The results obtained are shown expressed as lnjury Index in the following Table 6.

Table 6 Compound Number Name 1 2 3 4 5 s 9 10 ll l2 1] unof Plant treated Tobacco 0.2 0.3 0.3 0.2 0.7 0.3 0.4 0.5 0.5 0.4 0.3 0.4 0.5 4.0

Tomato 0.2 0.5 0.6 0.5 0.7 0.5 0.3 0.3 0.3 0.3 0.3 0.2 0.4 3.3

Egg-plant 0.4 0.3 0.2 0.2 0.6 0.4 0.3 0.4 0.4 0.4 0.5 0.3 0.2 3.3

Kidney Bean 0.3 0.4 0.5 0.6 0.4 0.5 0.6 0.5 0.5 0.5 0.6 0.4 0.3 4.4

Alfalfa 0.4 0.5 0.3 0.4 0.5 0.2 0.5 0.4 0.4 0.4 0.3 0.2 0.4 4.2

Rose 05 0.5 0.3 0.5 0.4 0.3 0.3 0.5 0.5 0.5 0.5 0,3 0.6 3.7

Garden Balsam 0.3 0.6 0.5 0.4 0.8 0.4 0.5 0.6 (1.6 0.6 0.7 0.4 0.4 3.5

Sage 0.4 0.4 0.7 0.7 0.9 0.7 0.6 0.3 0.8 0.6 0.8 0.5 0.8 4.1

Peach 0.1 0.2 0.3 0.3 0.4 0.2 0.3 0.1 0.1 0.2 0.2 0.3 0.1 1.9

Grape Vine 0.4 0.6 0.7 0.3 0.7 0.4 0.5 0.2 0.2 0.4 0.3 0.6 0.5 1.5

Japanese Cherry 0.2 0.3 0.5 0.5 0.9 0.2 0.3 0.4 0.4 0.4 0.5 0.3 0.6 1.3

Plane Tree 03 0.2 0.2 0.3 0.2 0.5 0.2 0.3 0.3 0.2 0.3 0.3 0.2 1.0

vated in a greenhouse in the same manner as described It is apparent from the results shown in the Table 6 in the above application Example 1 and tested 50 days that the protective agents 1 8 of this invention show after seeding. Rose (Rosa spp) which is 3 years old protective effects for oxidant injury for all of the plants after cutting and peach (Prunus persica sieb, er Zncc.), tested. Japanese cherry (Prunus Yedoensis Matsum) grape While the invention has been described in detail and vine Vl'tl's vinifera L.) and plane tree (Plamnus arienmwith reference to specific embodiments thereof. it will is L.) which appear to be mdre than 3 to 5 years old be apparent to one skilled in the art that various were used. and branches with leaves were cut therechanges and modifications can be made therein withfrom and put in bcakers filled with distilled water for out departing from the spirit and scope thereof. lestmg- What is claimed is:

Compounds 1 are prepared in the same way as m 1. A method of protecting plants against air oxidant the above Application Example I and sprayed on both I in to an kn em I surfaces of leaves of the respective plants. 3 days after mlury compnsmg app y g s I p pip y the treatment, the plants were exposed to air containbmoxlde' ing 30 pphm oxidant under the condition of an illumi- The method of clmm whel'clfl 531d Compound nation 20 000 l f and a temperature f 20 f 2 applied in the form of an cmulsifiablc concentrate or a hours and then placed in a greenhouse at l5C. After Wenablc p 48 hours. the degree of damage was observed. For the The method of claim Where!" 531d Plants are annual plants, the leaves observed were those situated bacco cgg'planb beam grape Vine in the lower one-fourth portion of the leaves above the ground. For the trees, the leaves observed were those situated in the lower one-fourth portion of the leaves of 40 n 

1. A METHOD OF PROTECTING PLANTS AGAINST AIR OXIDANT INJURY COMPRISING APPLYING TO SAID PLANTS PIPERONYL BUTOXIDE.
 2. The method of claim 1, wherein said compound is applied in the form of an emulsifiable concentrate or a wettable powder.
 3. The method of claim 1, wherein said plants are tobacco, tomato, egg-plant, kidney bean, grape vine or rose. 